In-Situ Testing of a Cement-Stabilized Metallurgical Residue

A large deposit of cement-stabilized jarosite was investigated by means of DMT as well as other in-situ tests (e.g. CPTu) and laboratory tests on core and block samples retrieved from the deposit. The material of dominant silt size, contains no silicates, has a large porosity and a relatively high (11%) cement content that results in a significant –but fragile- mechanical improvement. The deposit was built without resource to systematic compaction and the in-situ tests reveal significant inhomogeneities despite the industrial origin of the material. This paper examines the in situ test results focusing on basic index and state properties of the residue. The performance of correlations and interpretation methods well proven in conventional soils (i.e. silicate-based) is examined in detail. Particular attention is given to cement-induced apparent overconsolidation. The classical KD based correlation for clay appears to perform relatively well.